Latch means for loader lift arm support



g 13, 1968 H. w. BORER IETAL 3,396,863

LATCH MEANS FOR LOADER LIFT ARM SUPPORT Filed April 11, 1967 2 Sheets-Sheet l O 6 22 Q 20 '8 24 26 2 5l .1' -l- INVENTORS HERBERT W BORER FRANZ J. PROFIT By JAMES w. WHITE 2 -,a. ..bg$;, nz.z 1.1.

ATTORNEYS Aug. 13, 1968 w, BORER ET AL 3,396,863

LATCH MEANS FOR LOADER LIFT ARM SUPPORT Filed April 11, 1967 I 2 Sheets-Sheet 2 INVENTORS HERBERT W. BORER FRANZ J. PROFIT JAMES W. WHITE ATTORNEYS.

United States Patent ABSTRACT OF THE DISCLOSURE Latch means for a support which is used to prevent the lift arm of a tractor mounted bucket from descending when it is locked in a raised position.

There are occasions when it becomes necessary to raise the lift arms of a loader to enable men to work on repairs or replacements at the forward end of the loader tractor. Since the men so working are endangered by the mass of the arms and bucket suspended above them, it has been customary to lock the arms in their raised position so that they are not sustained only by hydraulic circuits the failure of which could permit them to fall. Various devices have been provided to hold loader lift arms in their raised position, one such device being disclosed in my assignees copending application of Borer and Ream for Loader Lift Arm Latch, Ser. No. 561,533, filed June 29, 1966. Another such means is disclosed in my assignees copending application of James Svoboda entitled Support for Loader Lift Arm, Ser. No. 564,055, filed July 11, 1966. The device of the present invention is designed to operate on the same principle as that of the last referred to application but includes certain improved features.

It is an object of the present invention to provide locking means of the kind described which has a latching device for holding it either in its operative position or its inoperative position and which latching device is convenient to actuate and has no parts which need be removed or which are likely to be lost during use.

A further object is to prevent removal of the locking or latching means or any part thereof without the use of a tool.

Further objects and advantages of the invention and a detailed description thereof are contained in the following specification wherein reference is made to the accompanying drawings.

In the drawings:

FIG. 1 is a view in side elevation of 'a loader showing the forward portion only of the tractor upon which it is mounted and showing the latch means of the present invention;

FIG. 2 is an enlarged fragmentary detail of the support and latch means therefor; and

FIG. 3 is a fragmentary detail partially in section taken on the line III-III of FIG. 2.

In FIG. 1 of the drawings, a tractor shown at 10 is illustrated as provided with loader frames, one of which is shown at 11. The loader frames are disposed on opposite sides of the tractor and each pivotally supports on opposite sides of the tractor and each pivotally supports a lift arm 12 at the outer end of which is pivoted a bucket 13. The lift arms and bucket are raised and lowered by a lift jack 14 in a conventional manner and tilt linkage, including a tilt jack 15, is provided for varying the attitude of the bucket about its pivotal connection with the lift arms. This mechanism is conventional and well known so that it need not be described in further detail except that an understanding of the present invention depends upon the operation of a lever ice 16 which forms a part of the tilt linkage. This lever acts as an anchor for the jack 15 so that extension and retraction of the jack is operable to vary the position of the bucket 13 from the dump position shown in FIG. 1 to a carry position and also to a load position. The lower ends of the levers 16 are connected as by links 18 with the loader frame 11. Thus upon raising and lowering of the lift arms 12, the position of the lever 16 is varied with respect to the lift arms and the bucket is held in one position which is generally the carry position as it is raised from the ground to the upper position without the necessity of actuating the tilt jack 15. This mechanism, generally referred to as automatic bucket position control, causes lever 16 to rotate in a counterclockwise direction -as lift arms 12 are lowered.

The support of the present invention prevents counterclockwise rotation of lever 16 and thus prevents lowering of lift arms 12. The support comprises, as shown in the drawing, a link 20 pivotally connected to a pin 22 which is also the'pivotal connection for the lift arms 12. The length of the pin has been increased slightly to accommodate the link. At its opposite end, the link 20 may be connected to a pivot pin 24 between the link 18 and lever 16 where it serves as a support because it prevents the lever 16 from rotating in a counterclockwise direction which is necessary to permit the lift arms 12 to be lowered. When the link 20 is not in use in this manner, it can be moved outwardly on the pin 22 which is longer than is necessary to support the link as best illustrated in FIG. 3. This outward movement enables the link 20 to clear the end of the pin 24 which extends outwardly from lever 16 a relatively short distance. According to the invention disclosed in the application of James Svoboda referred to above, when the link 20 was not in use, its end which embraces the pin 24 was moved to a pin 26 and the link thus had no function and was in a storage position. The link of the earlier application is held in either one of its two positions by a stud threaded into the end of either of the pins 24 or 26. Consequently the stud had to be removed with a tool and could easily be dropped to the ground between the tractor tracks or, during operation of the tractor while it was in its storage position, could loosen and become lost.

The present application provides latch means for holding the support link in either its operative or inoperative position. The arrangement is such that it is not necessary to swing the link away from either of the pins nor is it in fact possible to remove the link without the use of tools. There are no parts which need be removed to change the link from one position to the other.

This latch means is best shown in FIGS. 2 and 3 wherein a latch lever 28 is pivoted to the link 20 by a bolt 30 and biased to move in a clockwise direction about its pivot by a spring best shown at 31 in FIG. 3. The distal end of the latch lever 28 is received in a groove 33 of the pin 22 when the link 20 is in its operative position where it embraces both the pins 22 and 24 as illustrated in FIG. 3. To move the link 20* to its inoperative position, the latch lever 28 is swung counterclockwise in opposition to the force of spring 31 to release it from groove 33. The link is then pulled outwardly and the latch lever permitted to enter a second groove 35 retaining the link in a position Where its lower end clears the pin 24 thus rendering the support link inoperative. A stop 36 is secured to the loader frame 11 and the support link 20 rests on this stop when it is not in use.

To prevent the support link from being removed entirely, a stop 38 on the link itself is disposed to prevent retraction of the latch lever 28 to a point where its distal end can clear a flange 40 secured as by cap screws 42 to the outer end of the pin 22. It is thus possible for the support link to be moved between its operative and inoperative position with only one hand grasping the latch lever 28 and with no part being completely removable from the tractor so that dropping or losing a part is not possible.

We claim:

1. In a tractor mounted loader having lift and tilt means including two pivot pins movable relative to each other upon downward movement of the lift means, and a support link embracing both pins to prevent downward movement, one of said pins being longer than the other to enable the support link to move outwardly to an inoperative position where it clears the other pin, the improvement which comprises latch means acting between the support link and said one pin for retaining the link in either its operative or inoperative position thereon.

2. The combination of claim 1 in which the one pin has two grooves adjacent its outer end, and the latch means includes a pivoted latch lever and means to bias it into engagement in either of said grooves.

3. The combination of claim 2 in which the latch lever is on the link.

4. The combination of claim 3 with means to prevent removal of the link from the said one pin.

5. The combination of claim 4 in which the means to prevent includes a flange projecting radially outwardly at the need of the said pin and means to limit retraction of the latch at 'a position where it will engage the flange when the link is moved outwardly.

No references cited.

HUGO O. SCHULZ, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,396,863 August 13, 1968 Herbert W. Borer, et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 10, "need" should read end Signed and sealed'this' 3rdday of March 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR. 

